1. Field of Invention
The present invention relates to the field of computer and, in particular, to the field of touch pad.
2. Description of Prior Art
Nowadays, most notebook computers use touch pads as a component for realizing function selection such as “cursor navigation”, “selection” and “confirmation”. Typically, this component is based on capacitive sensing principle and is structured by designing and fabricating some electrodes on an upper surface of a PCB board and then placing a plastic board over the surface of the electrodes. With this structure, when a user draws on the plastic board with a finger or a touch pen, capacitance values at the electrodes will change accordingly. Consequently coordinate values of the finger or the touch pen on the PCB board and changes of these coordinate values can be detected. By mapping the detected coordinate values onto proper positions on a display screen, functions such as “cursor navigation” can be realized. Furthermore, currently known touch pads also include resistive touch pad and electromagnetic touch pad. Direct pressing is required by the resistive touch pad at the time of touching, and a dedicated electromagnetic pen is required by the electromagnetic touch pad.
For a long time, the touch pad has become a standard accessory of most notebook computers for its advantages such as stable performance and convenient operation. However, after so many years of development, this component still remains as a simple input device for computer without any additional computing and processing function in itself. For instance, it can not store certain specific operating data input by a user. It can not compare current operating data input by a user and those input by the user previously; therefore it can not make decision according to the comparison result. It can not identify different users, for example, by using graphical password technology. Specifically, when using the graphical password scheme, a user should draw a specific symbol on the touch pad in advance and use it as the data for identifying himself/herself. If the user wants to use the touch pad once again, he/she must first input the correct symbol. Only when the input symbol is authenticated, the touch pad can be used. In addition, this component itself does not have handwriting recognition capability; therefore it can not be used to input a corresponding password when a computer using this component is in a BIOS state.
In addition, certain specific operating data input by a user via the touch pad are stored and processed by recognition software running on a computer. Therefore, it is possible to identify different users by calculating and comparing the certain specific operating data input by the different users, and thus graphical password scheme works. However, this function only works after the computer has been booted up and begins to run the corresponding recognition software. In the course of booting up the computer or when the computer enters into the BIOS state, this function can not work.